136 THE SPRING GRAIN-APHIS OR " GREEN BUG." 



In 1890 the senior author, at Lafayette, Ind., found that the young 

 of the snowy tree-cricket {(Ecanthus niveus De G.) were very fond 

 of Toxoptera and fed upon them freely. 



Mr. A. N. Caudell, of this bureau, observed one of the soldier bugs, 

 Reduviolus ferns L., attacking Toxoptera on the grounds of the De- 

 partment of Agriculture at Washington in 1908. During the same 

 year Mr. C. N. Ainslie found a larva of a species of the ladybird genus 

 Scymnus at Mesilla Park, N. Mex., attacking Toxoptera, and he 

 seems to think that numbers are devoured by this insect. 



In 1909, at Washington, D. C, Mr. E. A. Yickery reared the 

 braconid Lipolexis piceus Cress, in limited numbers from Toxoptera. 



The junior author has at times found a fungous disease attacking the 

 aphidids in his rearing cages, but we have never noted this in the fields. 



ANTS AND THEIR RELATION TO TOXOPTERA. 



So far as our observations go Toxoptera is not so attractive to 

 ants as are many other species of plant-lice. We have often found 

 various species of ants in attendance on Toxoptera, but the relations 

 did not appear to be mutually beneficial, the ants nearly always 

 gaining the most by such partnerships. 



At Hooker, Okla., in 1907, the junior author found ant burrows 

 beside plants in an area badly infested with Toxoptera. In this case 

 some burrows were found where the aphidids were slightly below 

 ground on plants in these burrows, the ants being busy about the 

 aphidids, stroking them with their antennae. Mr. C. N. Ainslie many 

 times observed ants stroking Toxoptera with their antenna?. We have 

 found no instances, however, in which ants care for the eggs of Toxop- 

 tera in winter, and Toxoptera does not appear to excrete so much 

 honeydew as do some other aphidids. This probably accounts for the 

 fact that they are not so popular with the ants as are certain other 

 aphidids. 



In Texas, during 1909, Mr. T. D. Urbahns found ants busily caring 

 for Toxoptera in his rearing cages. He also noted that the ants al- 

 ways attacked the parasite of Toxoptera (ApJiidius sp.) whenever 

 they came in contact with it, tearing the larva? out of the old dead 

 bodies of Toxoptera and destroying them. 



REMEDIAL AND PREVENTIVE MEASURES. 



With an outbreak of this pest fully established, and the winged 

 adults being carried by the winds and scattered over the fields, there 

 to settle down and reproduce, the difficulties in the way of control 

 are quite insurmountable. 



FIELD EXPERIMENTS. 



The brush-drag experiments that were carried out under the direc- 

 tion of the junior author at Hobart, Okla. (see Plate IX, fig. 1), have 

 not, with the trials we have given the brush drag, proved satisfactory, 

 although Mr. Thos. J. Anderson, Government entomologist of British 



